1. Field of the Invention
The present disclosure relates to electrical machines, and more particularly to liquid cooled electrical machines.
2. Description of Related Art
Electrical machines commonly have rotor and stator portions separated by a gap. Each portion generates a magnetic field, typically using windings or permanent magnets, that interact with one another as the rotor portion rotates in relation to the stator. In generator machines, mechanical energy input to the rotor portion induces a current flow in the windings suitable for use as electrical power. In motor machines, current applied to windings induces a magnetic field that generates an electromotive force that causes the rotor portion to rotate in relation to the stator portion and output mechanical energy. In both types of machines, electric current flowing through the windings generates heat that needs to be dissipated for reliable operation of the electrical machine.
Some generators require coolant to facilitate dissipation of heat into the ambient environment. One approach involves coolant systems that apply a coolant spray to the winding ends. While satisfactory for cooling the windings in certain applications, such systems can allow coolant to infiltrate the gap between the rotor portion and stator portion where it can reduce efficiency by increasing windage losses in the gap.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved electrical machines and machine cooling systems. The present disclosure provides a solution for this need.